Introduction: To evaluate the efficacy of ferric carboxy maltose (FCM) in the treatment of iron deficiency/iron deficiency anaemia (ID/IDA) during pregnancy.Material and methods: Pregnant women ≥ 20 years old diagnosed with ID (serum ferritin < 15 μg/l) and moderate IDA were included in this study for correction of their ID/IDA. The participants received an FCM infusion for correction of their ID/IDA. The pre-treatment ferritin, haemoglobin (Hb), and red blood cell (RBC) indices were compared with the 6-and 12-week post-treatment values to evaluate the efficacy of FCM in the treatment of ID/IDA during pregnancy.Results: The pre-treatment ferritin and Hb significantly increased from 10.3 ±2.3 μg/l and 7.99 ±0.6 g/dl, respectively, to 139.5 ±1.9 and 14.04 ±0.45, respectively, 6-weeks after FCM infusion (p = 0.02 and 0.001, respectively), and to 128.9 ±1.7 and 13.02 ±0.5, respectively, 12-weeks after FCM infusion (p = 0.0008 and 0.02, respectively).In addition, the pre-treatment RBCs mean corpuscular volume and RBCs mean corpuscular haemoglobin (MCH) significantly increased from 72.02 ±3.5 fl and 23.9 ±1.9 pg, respectively, to 90.6 ± 2.8 fl and 29.98 ±1.5 pg, respectively, 6 weeks after FCM infusion (p = 0.01 and p = 0.007, respectively), and to 89.5 ±2.9 fl and 30.2 ±1.5 pg, respectively, 12 weeks after FCM infusion (p = 0.02 and 0.007 respectively).Conclusions: The ferric carboxy maltose was safe and effective for the treatment of ID/IDA during pregnancy within 6 weeks. The serum ferritin and Hb levels and the RBC indices remained significantly high 12 weeks after FCM infusion compared to the pre-treatment values.